The September 4 earthquake last year caused minor damage, and the family were in the process of drawing up plans to strengthen the 1930s building when the February quake struck and "cracked everything".

The building was red-stickered, but they had still hoped to save it before the June 13 aftershocks caused the old chapel to collapse.

"And the rest got destroyed by the digger," Lovell-Smith said.

They managed to save some stained-glass windows, which they planned to repair.

They had already spoken to an architect about a new building for the site, which could incorporate a few pieces that survived the quakes.

"We're trying to save elements of the convent because we really love the convent."

She said the family had started opening the 16-bedroom building to the community before the quakes by offering space for a regular belly-dancing class, and their rebuild plan would include the community again.

"We're hoping to build a big room like the chapel to fit the stained-glass windows in that can be used by the community."

Lovell-Smith's God Save the Queen! shop in Oxford St suffered significant damage in the February quake and was demolished.

Despite losing the home and business, Lovell-Smith said the family wanted to stay in Lyttelton and planned to rent until their home was rebuilt.

Demolition work is expected to begin on the nearby St Joseph's Church next week.

The 146-year-old building was red-stickered after last September's quake and each subsequent shake "gave it a fair whack", Father Denis Nolan said.

A service to farewell the historic church will be held at the site on Sunday at 12.15pm.